Polyphenylene ether-polyamide compositions from aryloxytriazine-capped polyphenylene ethers

ABSTRACT

Aryloxytriazine-capped polyphenylene ethers are prepared by reaction of a polyphenylene ether with an aryloxychlorotriazine such as diphenyl chlorocyanurate. The products undergo reaction with amine-terminated polymers such as polyamides, to form compositions which have excellent properties and which find utility as molding compositions and as compatibilizers for blends of similar polymers.

This invention relates to the preparation of aryloxytriazine-cappedpolyphenylene ethers.

The polyphenylene ethers are a widely used class of thermoplasticengineering resins characterized by excellent hydrolytic stability,dimensional stability, toughness, heat resistance and dielectricproperties. However, they are deficient in certain other properties suchas workability and solvent resistance. Therefore, there is a continuingsearch for means for modifying polyphenylene ethers to improve theseother properties.

A disadvantage of the polyphenylene ethers which militates against theiruse for molding such items as automotive parts is their low resistanceto non-polar solvents such as gasoline. For increased solventresistance, it would be desirable to form compositions in whichpolyphenylene ethers are combined with resins which have a high degreeof crystallinity and therefore are highly resistant to solvents.Illustrative of such resins are the thermoplastic polyamides. Otherreasons exist for forming compositions comprising polyphenylene ethersand such other polyamides as the amorphous and elastomeric species.

However, polyphenylene oxide-polyamide blends frequently undergo phaseseparation and delamination. They typically contain large, incompletelydispersed polyphenylene ether particles and no phase interaction betweenthe two resin phases. Molded parts made from such blends are typicallycharacterized by extremely low impact strength, brittleness,delamination and the like.

Numerous methods for compatibilizing polyphenylene ether-polyamidecompositions have been developed. For example, U.S. Pat. No. 4,315,086and copending, commonly owned application Ser. No. 736,489, filed May20, 1985, describe the use for this purpose of various polyfunctionalcompounds, including olefinic and acetylenic carboxylic acids,polycarboxylic acids and functional derivatives thereof.

A very effective way of compatibilizing polyphenylene ether-polyamidecompositions is by the formation of a copolymer of the two resins. Thismay be achieved by the incorporation of a polyamide-reactive functionalgroup on the polyphenylene ether. Groups suitable for this purposeinclude carboxylic acid groups as in U.S. Pat. Nos. 4,600,741 and4,732,938 and copending, commonly owned application Ser. No. 885,497,filed July 14, 1986.

Another particularly suitable polyamide-reactive functional group is theepoxy group. Various methods of attaching epoxy groups to polyphenyleneethers have been disclosed. For example, U.S. Pat. No. 4,460,743describes the reaction of a polyphenylene ether with epichlorohydrin;U.S. Pat. No. 4,732,937 the reaction with terephthaloyl chloride andglycidol; copending, commonly owned application Ser. No. 912,705, filedSept. 29, 1986, the reaction with various epoxy-functionalized ethylenicmonomers such as glycidyl acrylate, glycidyl methacrylate and allylglycidyl ether in the presence of free radical initiators; andapplication Ser. No. 286,184, filed Dec. 19, 1988, the reaction with anepoxychlorotriazine.

It has now been discovered that certain aryloxytriazine-cappedpolyphenylene ethers form compatible, ductile compositions havingrelatively high impact strengths and other favorable properties whenblended with polyamides. It is believed that a copolymer of thepolyphenylene ether with the polyamide is formed by displacement of anaryloxy group by an amine end group in the polyamide.

In one of its aspects, therefore, the invention includes compositionscomprising at least one polyamide and at least onearyloxytriazine-capped polyphenylene ether having end groups of theformula ##STR1## wherein: each Q¹ is independently halogen, primary orsecondary lower alkyl, phenyl, haloalkyl, aminoalkyl, hydrocarbonoxy, orhalohydrocarbonoxy wherein at least two carbon atoms separate thehalogen and oxygen atoms;

each Q² is independently hydrogen, halogen, primary or secondary loweralkyl, phenyl, haloalkyl, hydrocarbonoxy or halohydrocarbonoxy asdefined for Q¹ ;

A is an unsubstituted or substituted aromatic radical; and

X is an alkyl or cycloalkyl radical or an unsubstituted or substitutedaromatic radical.

Aryloxytriazine-capped polyphenylene ethers suitable for use in thepreparation of the compositions of this invention, as well as methodsfor their preparation, are disclosed and claimed in copending, commonlyowned application Ser. No. 319,393, filed Mar. 6, 1989. They may beprepared from polyphenylene ethers known in the art. The latterencompass numerous variations and modifications all of which areapplicable to the present invention, including but not limited to thosedescribed hereinafter.

The polyphenylene ethers comprise a plurality of structural units havingthe formula ##STR2## and in each of said units independently, each Q¹ ;and Q² is as previously defined. Examples of primary lower alkyl groupssuitable as Q¹ and Q² are methyl, ethyl, n-propyl, n-butyl, isobutyl,n-amyl, isoamyl, 2-methylbutyl, n-hexyl, 2,3-dimethylbutyl, 2-, 3- or4-methylpentyl and the corresponding heptyl groups. Examples ofsecondary lower alkyl groups are isopropyl, sec-butyl and 3-pentyl.Preferably, any alkyl radicals are straight chain rather than branched.Most often, each Q¹ is alkyl or phenyl, especially C₁₋₄ alkyl, and eachQ² is hydrogen. Suitable polyphenylene ethers are disclosed in a largenumber of patents.

Both homopolymer and copolymer polyphenylene ethers are included.Suitable homopolymers are those containing, for example,2,6-dimethyl-1,4-phenylene ether units. Suitable copolymers includerandom copolymers containing such units in combination with (forexample) 2,3,6-trimethyl-1,4-phenylene ether units. Many suitable randomcopolymers, as well as homopolymers, are disclosed in the patentliterature.

Also included are polyphenylene ethers containing moieties which modifyproperties such as molecular weight, melt viscosity and/or impactstrength. Such polymers are described in the patent literature and maybe prepared by grafting onto the polyphenylene ether in known mannersuch vinyl monomers as acrylonitrile and vinylaromatic compounds (e.g.,styrene), or such polymers as polystyrenes and elastomers. The producttypically contains both grafted and ungrafted moieties. Other suitablepolymers are the coupled polyphenylene ethers in which the couplingagent is reacted in known manner with the hydroxy groups of twopolyphenylene ether chains to produce a higher molecular weight polymercontaining the reaction product of the hydroxy groups and the couplingagent, provided substantial proportions of free hydroxy groups remainpresent. Illustrative coupling agents are low molecular weightpolycarbonates, quinones, heterocycles and formals.

The polyphenylene ether generally has a number average molecular weightwithin the range of about 3,000-40,000 and a weight average molecularweight within the range of about 20,000-80,000, as determined by gelpermeation chromatography. Its intrinsic viscosity is most often in therange of about 0.15-0.6 dl./g., as measured in chloroform at 25° C.

The polyphenylene ethers are typically prepared by the oxidativecoupling of at least one corresponding monohydroxyaromatic compound.Particularly useful and readily available monohydroxyaromatic compoundsare 2 6-xylenol (wherein each Q¹ is methyl and each Q² is hydrogen),whereupon the polymer may be characterized as apoly(2,6-dimethyl-1,4-phenylene ether), and 2,3,6-trimethylphenol(wherein each Q¹ and one Q² are methyl and the other Q² is hydrogen).

A variety of catalyst systems are known for the preparation ofpolyphenylene ethers by oxidative coupling. There is no particularlimitation as to catalyst choice and any of the known catalysts can beused. For the most part, they contain at least one heavy metal compoundsuch as a copper, manganese or cobalt compound, usually in combinationwith various other materials.

A first class of preferred catalyst systems consists of those containinga copper compound. Such catalysts are disclosed, for example, in U.S.Pat. Nos. 3,306,874, 3,306,875, 3,914,266 and 4,028,341. They areusually combinations of cuprous or cupric ions, halide (i.e., chloride,bromide or iodide) ions and at least one amine.

Catalyst systems containing manganese compounds constitute a secondpreferred class. They are generally alkaline systems in which divalentmanganese is combined with such anions as halide, alkoxide or phenoxide.Most often, the manganese is present as a complex with one or morecomplexing and/or chelating agents such as dialkylamines, alkanolamines,alkylenediamines, o-hydroxyaromatic aldehydes o-hydroxyazo compounds,ω-hydroxyoximes (monomeric and polymeric), o-hydroxyaryl oximes andβ-diketones. Also useful are known cobalt-containing catalyst systemsSuitable manganese and cobalt-containing catalyst systems forpolyphenylene ether preparation are known in the art by reason ofdisclosure in numerous patents and publications.

Particularly useful polyphenylene ethers for the purposes of thisinvention are those which comprise molecules having at least one of theend groups of the formulas ##STR3## wherein Q¹ and Q² are as previouslydefined; each R¹ is independently hydrogen or alkyl, with the provisothat the total number of carbon atoms in both R¹ radicals is 6 or less;and each R² is independently hydrogen or a C₁₋₆ primary alkyl radicals.Preferably, each R¹ is hydrogen and each R² is alkyl, especially methylor n-butyl.

Polymers containing the aminoalkyl-substituted end groups of formula IIImay be obtained by incorporating an appropriate primary or secondarymonoamine as one of the constituents of the oxidative coupling reactionmixture, especially when a copper- or manganese-containing catalyst isused. Such amines, especially the dialkylamines and preferablydi-n-butylamine and dimethylamine, frequently become chemically bound tothe polyphenylene ether, most often by replacing one of the α-hydrogenatoms on one or more Q¹ radicals. The principal site of reaction is theQ¹ radical adjacent to the hydroxy group on the terminal unit of thepolymer chain. During further processing and/or blending, theaminoalkyl-substituted end groups may undergo various reactions,probably involving a quinone methide-type intermediate of the formula##STR4## with numerous beneficial effects often including an increase inimpact strength and compatibilization with other blend components.Reference is made to U.S. Pat. Nos. 4,054,553, 4,092,294, 4,477,649,4,477,651 and 4,517,341, the disclosures of which are incorporated byreference herein.

Polymers with 4-hydroxybiphenyl end groups of formula IV are typicallyobtained from reaction mixtures in which a by-product diphenoquinone ofthe formula ##STR5## is present, especially in a copper-halide-secondaryor tertiary amine system. In this regard, the disclosure of U.S. Pat.No. 4,477,649 is again pertinent as are those of U.S. Pat Nos. 4,234,706and 4,482,697, which are also incorporated by reference herein. Inmixtures of this type, the diphenoquinone is ultimately incorporatedinto the polymer in substantial proportions, largely as an end group.

In many polyphenylene ethers obtained under the above-describedconditions, a substantial proportion of the polymer molecules, typicallyconstituting as much as about 90% by weight of the polymer, contain endgroups having one or frequently both of formulas III and IV. It shouldbe understood, however, that other end groups may be present and thatthe invention in its broadest sense may not be dependent on themolecular structures of the polyphenylene ether end groups, provided asubstantial proportion of free hydroxy groups is present.

It will be apparent to those skilled in the art from the foregoing thatthe polyphenylene ethers contemplated for use in the present inventioninclude all those presently known, irrespective of variations instructural units or ancillary chemical features.

The end groups on the aryloxytriazine-capped polyphenylene ethers haveformula I, in which Q¹ and Q² are as previously defined. The X value maybe an alkyl or cycloalkyl radical, typically lower alkyl, or an aromaticradical, typically containing 6-10 carbon atoms and especially anaromatic hydrocarbon radical; and A is an identical aromatic radical ora different radical of the same type.

When X is an alkyl or cycloalkyl radical, it is often preferablysterically hindered to prevent nucleophilic attach on said radical bythe amino nitrogen atom of the polyamide, to form an alkylated aminegroup. Sterically hindered radicals include secondary and tertiaryradicals, as well as primary alkyl radicals which are highly branched onatoms close to the 1-carbon atom; e.g., neoalkyl.

Most often, both A and X are phenyl or are substituted phenyl.Substituted phenyl groups in which the substituents have severalidentical hydrogen atoms, such as t-butylphenyl and methoxyphenyl, havethe advantage of affording products in which the proportion of cappingmay be determined by proton nuclear magnetic resonance, utilizing theprotons on the t-butyl or methoxy group. (The same is true when X ismethyl or t-butyl.) On the other hand, electron-withdrawing substituentssuch as halo, carboxy, carbalkoxy, nitrile, nitro, acyl and aldehydegroups may promote displacement by the amine groups in the polyamide byreason of the lower pKa of the conjugate acid of the displaced aryloxideanion.

The aryloxytriazine-capped polyphenylene ether compositions may beprepared by contacting under reactive conditions, in the presence of abasic reagent, at least one polyphenylene ether with anaryloxychlorotriazine of the formula ##STR6## wherein A and X are aspreviously defined. Typical aryloxychlorotriazines of formula VIIinclude 2-chloro-4,6-diphenoxy-1,3,5-triazine,2-chloro-4,6-di-(4-t-butylphenoxy)-1,3,5-triazine and2-chloro-4,6-di-(4-methoxyphenoxy)-1,3,5-triazine. These compounds mayalso be named as though derived from cyanuric acid and designateddiphenyl chlorocyanurate, di-(4-t-butylphenyl) chlorocyanurate anddi-(4-methoxyphenyl) chlorocyanurate, respectively. They may beprepared, for example, by the reaction of 2,4,6-trichlorotriazine(cyanuric chloride) with the corresponding hydroxyaromatic compounds, orsequentially with hydroxyaromatic compounds and aliphatic or alicyclicalcohols. Their preparation is illustrated by the following examples;all percentages in the examples herein are by weight.

EXAMPLE 1

A 1-liter Morton flask fitted with a dropping funnel and mechanicalstirrer was charged with 59 grams (320 mmol.) of cyanuric chloride, 60.2grams (640 mmol.) of phenol and 400 ml. of methylene chloride. There wasadded over 1 hour, with vigorous stirring, a solution of 25.6 grams (640mmol.) of sodium hydroxide in 110 ml. of water, as the flask was cooledin an ice bath.

When base addition was complete, the ice bath was removed and stirringwas continued for 1 hour, after which the organic layer was separated,washed once with dilute sodium hydroxide solution and twice with sodiumchloride solution and dried over magnesium sulfate. Upon filtration andevaporation of the methylene chloride, there was obtained 90.4 grams(94% of theoretical) of crude diphenyl chlorocyanurate. It was shown byhigh pressure liquid chromatography to contain about 4% triphenylcyanurate as an impurity. A sample recrystallized from heptane had amelting point of 118°-120° C. (literature value 121°-123° C.).

EXAMPLE 2

The procedure of Example 1 was repeated, employing 105.8 grams (700mmol.) of 4-t-butylphenol in place of the phenol, employing 28.2 grams(700 mmol.) of sodium hydroxide and stirring for 30 minutes after sodiumhydroxide addition was complete. There was obtained 116.3 grams (84% oftheoretical, assuming pure product) of the desired di-(4 t-butylphenyl)chlorocyanurate.

EXAMPLE 3

The procedure of Example 2 was repeated, except that 4-methoxyphenol wassubstituted for the 4-t-butylphenol, base was added over 11/4 hours andthe mixture was subsequently stirred for 1 hour. There was obtained 88.2grams (73% of theoretical, assuming pure product) of the desired crudedi-(4-methoxyphenyl) chlorocyanurate.

Various options are available for the reaction of the polyphenyleneether with the aryloxychlorotriazine. In one option, the reaction isconducted in solution in a non-polar organic liquid, typically at atemperature in the range of about 80°-150° C. and preferably about100°-125° C. The basic reagent employed in this embodiment should besoluble in the organic liquid and is generally a tertiary amine. Itsidentity is not otherwise critical, provided it is sufficientlynon-volatile to remain in the reaction mixture at the temperaturesemployed. Pyridine is often preferred.

The amount of aryloxychlorotriazine employed in this option is generallyin the range of about 1-20% by weight, based on polyphenylene ether. Theamount of basic reagent is an effective amount to promote the reaction;in general, about 1.0-1.1 equivalent thereof per mole ofaryloxychlorotriazine is adequate.

In a second, preferred option, the reaction is conducted interfaciallyin a medium comprising water and an organic liquid as previouslydescribed. The basic reagent is a water-soluble base, typically analkali metal hydroxide and preferably sodium hydroxide. It may be addedto the mixture of aryloxychlorotriazine and polyphenylene ether, or mayinitially react with the polyphenylene ether to form a salt which isthen contacted with the aryloxychlorotriazine. There is also employed aphase transfer catalyst. Any of such catalysts which are stable andeffective under the prevailing reaction conditions may be used; thoseskilled in the art will readily perceive which ones are suitable.Particularly preferred are tetraalkylammonium chlorides wherein at leasttwo alkyl groups per molecule, typically 2 or 3, contain about 5-15carbon atoms.

In this option, reaction temperatures in the range of about 20°-70° C.may be employed. The amount of aryloxychlorotriazine is frequently lowerthan in the previously described embodiment, typically in the range ofabout 1-6% and preferably about 2-6% by weight based on polyphenyleneether, since the reaction of the aryloxychlorotriazine with thepolyphenylene ether apparently proceeds more nearly to completion. Mostoften, the ratio of equivalents of base to moles ofaryloxychlorotriazine is about 1.0-1.5:1, and the weight ratio of phasetransfer catalyst to polyphenylene ether is about 0.01-0.03:1. It isfrequently preferred to neutralize the reaction mixture with anyconvenient acidic compound; carbon dioxide, in gaseous, liquid or solidform, is generally suitable.

The preparation of the aryloxytriazine-capped polyphenylene ethers isillustrated by the following examples. The degrees of capping in thecapped polymers were determined by Fourier transform infrared or nuclearmagnetic resonance spectroscopy. The polyphenylene ether employed was apoly(2,6-dimethyl-1,4-phenylene ether) having an intrinsic viscosity inchloroform at 25° C. of 0.40 dl./g.

EXAMPLE 4

To a solution of 400 grams of polyphenylene ether in 2500 ml. of toluenewas added 48 grams of a 10% solution in toluene of a commerciallyavailable methyltrialkylammonium chloride in which the alkyl groupscontained 8-10 carbon atoms and 16 grams of crude2-chloro-4,6-diphenoxy-1,3,5-triazine. The resulting solution wasvigorously stirred as 24 grams of 10% aqueous sodium hydroxide solution(60 mmol.) was added dropwise over 5 minutes. The mixture was stirredfor 30 minutes, after which the organic layer was separated and thecapped polyphenylene ether was precipitated by treatment with methanolin a blender. The precipitated product was filtered, washed withmethanol and dried in vacuum at 90°-110° C. Fourier transform infraredspectroscopic analysis showed the absence of free hydroxy end groups inthe product.

EXAMPLES 5-8

Following the procedure of Example 4, reactions were conducted betweenpolyphenylene ether and various chlorotriazines, identified in Table Ihereinafter by the identities of the X and A groups. After sodiumhydroxide addition was complete and the mixtures had been stirred forabout 1/2 hour, they were neutralized by saturation with carbon dioxidegas while stirring and the capped polyphenylene ethers were isolated aspreviously described. The relevant parameters and test results are givenin Table I.

                  TABLE I                                                         ______________________________________                                        Aryloxychlorotriazine                                                                            Sodium    %                                                        Phenyl             hydroxide,                                                                            triazine                                   Example substituent                                                                              %       mmol.   incorporated*                              ______________________________________                                        5       4-t-Butyl  3       44      2.27                                       6       4-t-Butyl  4.5     44      2.79                                       7       4-t-Butyl  5       44      2.77                                       8       4-Methoxy  4       47      2.35                                       ______________________________________                                         *Based on polyphenylene ether.                                           

The aryloxytriazine-capped polyphenylene ethers form compatible, ductilecompositions of this invention with amine-terminated polymers),especially polyamides. Any polyamide made by any known method may beused, provided it contains a substantial proportion of amine end groups.In many instances, polyamides in which the amine end group concentrationis at least about 60 meq./g. are particularly useful.

Suitable polyamides include those of the type prepared by thepolymerization of a monoamino-monocarboxylic acid or a lactam thereofhaving at least 2 carbon atoms between the amino and carboxylic acidgroup, of substantially equimolar proportions of a diamine whichcontains at least 2 carbon atoms between the amino groups and adicarboxylic acid, or of a monoaminocarboxylic acid or a lactam thereofas defined above together with substantially equimolar proportions of adiamine and a dicarboxylic acid. The dicarboxylic acid may be used inthe form of a functional derivative thereof, for example, an ester oracid chloride.

Examples of the aforementioned monoamino-monocarboxylic acids or lactamsthereof which are useful in preparing the polyamides include thosecompounds containing from 2 to 16 carbon atoms between the amino andcarboxylic acid groups, said carbon atoms forming a ring with the-CO-NH-group in the case of a lactam. As particular examples ofaminocarboxylic acids and lactams there may be mentioned ε-aminocaproicacid, butyrolactam, pivalolactam, ε-caprolactam, capryllactam,enantholactam, undecanolactam, dodecanolactam and 3- and 4-aminobenzoicacids.

Diamines suitable for use in the preparation of the polyamides includethe straight chain and branched chain alkyl, aryl and alkaryl diamines.Illustrative diamines are trimethylenediamine, tetramethylenediamine,pentamethylenediamine, ocaamethylenediamine, hexamethylenediamine (whichis often preferred), trimethylhexamethylenediamine, m-phenylenediamineand m-xylylenediamine.

Suitable dicarboxylic acids include those which contain an aliphatic oraromatic group containing at least 2 carbon atoms separating the carboxygroups. The aliphatic acids are often preferred; they include sebacicacid, octadecanedioic acid, suberic acid, glutaric acid, pimelic acidand adipic acid.

Both crystalline and amorphous polyamides may be employed, with thecrystalline species often being preferred by reason of their solventresistance. Typical examples of the polyamides or nylons, as these areoften called, include, for example, polyamide-6 (polycaprolactam), 66(polyhexamethylene adipamide), 11, 12, 63, 64, 6/10 and 6/12 as well aspolyamides from terephthalic acid and/or isophthalic acid andtrimethylhexamethylenediamine; from adipic acid and m-xylylenediamines;from adipic acid, azelaic acid and 2,2-bis(p-aminophenyl)propane or2,2-bis-(p-aminocyclohexyl)propane and from terephthalic acid and4,4'-diaminodicyclohexylmethane. Mixtures and/or copolymers of two ormore of the foregoing polyamides or prepolymers thereof, respectively,are also within the scope of the present invention. Preferred polyamidesare polyamide-6, 66, 11 and 12, most preferably polyamide-66.

For the preparation of the compositions of this invention, a blendingmethod which results in the formation of an intimate blend is highlypreferred. Suitable procedures include solution blending, although suchprocedures are of limited applicability to many polyamides by reason oftheir insolubility in most common solvents. For this reason and becauseof the availability of melt blending equipment in commercial polymerprocessing facilities, melt reaction procedures are generally preferred.Conventional melt blending procedures and equipment may be employed,with extrusion often preferred because of its relative convenience andparticular suitability. Typical reaction temperatures are in the rangeof about 175°-350° C.

Those skilled in the art will be familiar with blending methods andapparatus capable of intimately blending resinous constituents,especially by kneading. They are exemplified by disc-pack processors andvarious types of extrusion equipment. Illustrations of the latter arecontinuous mixers; single screw kneading extruders; corotating,intermeshing and counterrotating, non-intermeshing twin screw extrudershaving such features as staggered configuration screws, forward-flightedcompounders, cylindrical bushings and left-handed screw elements; andextruders having screws which include at least one and preferably twokneading block elements.

It is within the scope of the invention to include in the blending stepelastomeric impact modifiers compatible with either or both of thepolyphenylene ether and the polyamide.

Impact modifiers for polyphenylene ether-polyamide compositions are wellknown in the art. They are typically derived from one or more monomersselected from the group consisting of olefins, vinyl aromatic monomers,acrylic and alkylacrylic acids and their ester derivatives as well asconjugated dienes. Especially preferred impact modifiers are the rubberyhigh-molecular weight materials including natural and syntheticpolymeric materials showing elasticity at room temperature. They includeboth homopolymers and copolymers, including random, block, radial block,graft and core-shell copolymers as well as combinations thereof.

Polyolefins or olefin-based copolymers employable in the inventioninclude low density polyethylene, high density polyethylene, linear lowdensity polyethylene, isotactic polypropylene, poly(1-butene),poly(4-methyl-1-pentene), propylene-ethylene copolymers and the like.Additional olefin copolymers include copolymers of one or moreα-olefins, particular)y ethylene, with copolymerizable monomersincluding, for example, vinyl acetate, acrylic acid and alkylacrylicacids as well as the ester derivatives thereof including, for example,ethyl acrylate, methyl methacrylate and the like. Also suitable are theionomer resins, which may be wholly or partially neutralized with metalions.

A particularly useful class of impact modifiers are those derived fromthe vinyl aromatic monomers. These include AB and ABA type block andradial block copolymers and vinyl aromatic conjugated diene core-shellgraft copolymers.

An especially preferred subclass of vinyl aromatic monomer-derivedresins is the block copolymers comprising monoalkenyl arene (usuallystyrene) blocks and conjugated diene (e.g., butadiene or isoprene) orolefin (e.g., ethylenepropylene, ethylene-butylene) blocks andrepresented as AB and ABA block copolymers. The conjugated diene blocksmay be partially or entirely hydrogenated, whereupon the properties aresimilar to the olefin block copolymers.

Suitable AB type block copolymers are disclosed in, for example, U.S.Pat. Nos. 3,078,254; 3,402,159; 3,297,793; 3,265,765 and 3,594,452 andUK Patent No. 1,264,741, all incorporated herein by reference. Exemplaryof typical species of AB block copolymers are polystyrene-polybutadiene(SBR), polystyrene-polyisoprene andpoly(alpha-methylstyrene)polybutadiene. Such AB block copolymers areavailable commercially from a number of sources, including PhillipsPetroleum under the tradename SOLPRENE.

Additionally, ABA triblock copolymers and processes for their productionas well as hydrogenation, if desired, are disclosed in U.S. Pat. Nos.3,149,182; 3,231,635; 3,462,162; 3,287,333; 3,595,942; 3,694,523 and3,842,029, all incorporated herein by reference.

Examples of triblock copolymers includepolystyrene-polybutadiene-polystyrene (SBS),polystyrene-polyisoprene-polystyrene (SIS),poly(α-methylstyrene)-polybutadiene-poly(α-methylstyrene) andpoly(α-methylstyrene)-polyisoprene-poly(α-methylstyrene). Particularlypreferred triblock copolymers are available commercially as CARIFLEX®,KRATON D® and KRATON G® from Shell.

Another class of impact modifiers is derived from conjugated dienes.While many copolymers containing conjugated dienes have been discussedabove, additional conjugated diene modifier resins include, for example,homopolymers and copolymers of one or more conjugated dienes including,for example, polybutadiene, butadiene-styrene copolymers,isoprene-isobutylene copolymers, chlorobutadiene polymers,butadiene-acrylonitrile copolymers, polyisoprene, and the like.Ethylene-propylene-diene monomer rubbers may also be used. These EPDM'sare typified as comprising predominantly ethylene units, a moderateamount of propylene units and up to about 20 mole percent ofnon-conjugated diene monomer units. Many such EPDM's and processes forthe production thereof are disclosed in U.S. Pat. Nos. 2,933,480;3,000,866; 3,407,158; 3,093,621 and 3,379,701, incorporated herein byreference.

Other suitable impact modifiers are the core-shell type graftcopolymers. In general, these have a predominantly conjugated dienerubbery core or a predominantly cross-linked acrylate rubbery core andone or more shells polymerized thereon and derived from monoalkenylareneand/or acrylic monomers alone or, preferably, in combination with othervinyl monomers. Such core-shell copolymers are widely availablecommercially, for example, from Rohm and Haas Company under the tradenames KM-611, KM-653, KM-330, and are described in U.S. Pat. Nos.3,808,180; 4,034;013; 4,096,202; 4,180,494 and 4,292,233.

Also useful are the core-shell copolymers wherein an interpenetratingnetwork of the resins employed characterizes the interface between thecore and shell. Especially preferred in this regard are the ASA typecopolymers available from General Electric Company and sold as GELOY™resin and described in U.S. Pat. No. 3,944,631.

In addition, there may be employed the above-described polymers andcopolymers having copolymerized therewith or grafted thereon monomershaving functional groups and/or polar or active groups. Finally, othersuitable impact modifiers include Thiokol rubber, polysulfide rubber,polyurethane rubber, polyether rubber (e.g., polypropylene oxide),epichlorohydrin rubber, ethylene-propylene rubber, thermoplasticpolyester elastomers and thermoplastic etherester elastomers.

The proportion of impact modifier or other resinous material is subjectto wide variation. Impact modifiers such as diblock or triblockcopolymers are usually present in an amount up to about 50 parts per 100parts of polyphenylene ether.

The order of blending may be varied. It is often found advantageous toemploy an extruder which has at least two ports for introduction ofingredients, one such port being downstream from the other. The cappedpolyphenylene ether and at least a portion of the impact modifier areintroduced through the first port and extruded. This portion of theextruder is often preferably vacuum vented.

The polyamide and any additional impact modifier are introduced throughthe downstream port and extrusion is continued, preferably at a lowertemperature to minimize degradation of the impact modifier. By thismethod, optimum dispersion may be achieved.

It is believed that the polyphenylene etherpolyamide compositions ofthis invention owe their compatibility and favorable properties in largepart to copolymer formation, as a result of displacement of aryloxideanions from the triazine ring by the highly nucleophilic amine endgroups of the polyamide. So far as is known, this is the first instanceof the formation of such a copolymer by a simple nucleophilicdisplacement reaction. Thus, said amine groups are believed to react toform copolymer molecules containing linkages of the formula ##STR7##wherein Q¹ and Q² are as previously defined and Z is an alkyl orcycloalkyl or unsubstituted or substituted aromatic radical or -NH-.Compositions comprising such copolymers are another aspect of theinvention.

The proportions of polyphenylene ether and polyamide are not critical;they may be widely varied to provide compositions having the desiredproperties. Most often, each polymer is employed in an amount in therange of about 5-95%, preferably about 30-70%, of the composition byweight.

For the most part, the compositions of this invention are believed tocontain various proportions of polyphenylene ether and polyamidehomopolymers in addition to copolymer. This may be the result ofincorporation of excess polyamide or unfunctionalized polyphenyleneether therein, incomplete capping of the polyphenylene ether, orincomplete reaction of capped polyphenylene ether with polyamide. In anyevent, molded parts produced from said compositions are generallyductile and have higher impact strengths than those produced from simplepolyphenylene ether-polyamide blends, which are incompatible and oftenexhibit brittleness or delamination as previously described.

There may also be present in the compositions of this inventionconventional ingredients such as fillers, flame retardants, pigments,dyes, stabilizers, anti-static agents, crystallization aids, moldrelease agents and the like, as well as resinous components notpreviously discussed.

The preparation of the compositions of this invention is illustrated bythe following examples. All parts and percentages are by weight. Theimpact modifier used in each example, unless otherwise specified, was acommercially available triblock copolymer with polystyrene end blockshaving weight average molecular weights of 29,000 and a hydrogenatedbutadiene midblock having a weight average molecular weight of 116,000.

EXAMPLES 9-10

Blends of 49% of the aryloxytriazine-capped polyphenylene ether ofExample 4, 41% of various commercially available polyamide-66 resinshaving amine end group concentrations less than 60 meq./g. and 10%impact modifier were mixed on a jar mill for 15 minutes and extruded ona 20-mm. counterrotating, non-intermeshing twin screw extruder, attemperatures from 120° C. to 290° C. The extrudates were quenched inwater, pelletized, dried for 2-4 hours at 100°-120° C. and molded intotest specimens which were tested for notched Izod impact strength andtensile properties (ASTM procedures D256 and D638, respectively) andheat distortion temperature at 0.455MPa. (ASTM procedure D648).

The test results are given in Table II, in comparison with a control inwhich the aryloxytriazine-capped polyphenylene ether was replaced by anuncapped polyphenylene ether having an intrinsic viscosity of 0.43dl./g. No delamination of any test specimen was observed.

                  TABLE II                                                        ______________________________________                                                        Example                                                                       9     10       Control                                        ______________________________________                                        Polyamide         66      6        66                                         Izod impact strength, joules/m.                                                                 710     716      16                                         Tensile strength, MPa.:                                                       At yield          53.8    52.6     51.1                                       At break          62.0    61.5     51.1                                       Tensile elongation, %                                                                           175     219      11                                         Heat distortion temp., °C.                                                               190     --       --                                         ______________________________________                                    

The improvement in impact strength of the compositions of thisinvention, as compared to the control, is evident. Tensile propertiesare also superior, as evidenced by the increase in elongation and thesubstantially higher tensile strength at break than at yield, incomparison with the control which was brittle and whose break and yieldvalues were identical.

EXAMPLES 11-16

Polyphenylene ether-polyamide compositions similar to those of Examples9-10 were prepared from the aryloxytriazine-capped polyphenylene etherof Example 5, impact modifier and various commercially availablepolyamide-6 and polyamide-66 resins having amine end groupconcentrations below and above 60 meq./g. (designated "L" and "H",respectively).

The test results are given in Table III, in comparison with controlsprepared from uncapped polyphenylene ether. No delamination wasobserved, except for slight skin delamination in Examples 15 and 16.

                                      TABLE III                                   __________________________________________________________________________                Example     Control                                                                            Example     Control                                          11  12  13  1    14  15  16  2                                    __________________________________________________________________________    Polyphenylene ether, %:                                                       Uncapped    --  --  --  49   --  --  24.5                                                                              49                                   Ex. 5       49  49  49  --   49  49  24.5                                                                              --                                   Polyamide, %:                                                                 66 L        41  --  20.5                                                                              --   --  20.5                                                                              --  --                                   66 H        --  41  20.5                                                                              41   --  --  --  --                                   6 H         --  --  --  --   41  20.5                                                                              41  41                                   Izod impact strength,                                                                     192 753 230 37   945 983 924 48                                   joules/m.                                                                     Tensile strength, MPa.:                                                       At yield    52.3                                                                              53.3                                                                              51.7                                                                              52.4 52.3                                                                              50.2                                                                              53.0                                                                              49.6                                 At break    54.0                                                                              55.6                                                                              53.2                                                                              52.4 56.9                                                                              57.3                                                                              56.3                                                                              46.8                                 Tensile elongation, %                                                                     111 122 101 11   179 195 158 19                                   __________________________________________________________________________

EXAMPLES 17-18

The procedure of Examples 9-10 was repeated, substituting thearyloxytriazine-capped polyphenylene ether of Example 8 for that ofExample 4. The results are given in Table IV; no delamination wasobserved.

                  TABLE IV                                                        ______________________________________                                                           Example                                                                       17    18                                                   ______________________________________                                        Polyamide            66L     6H                                               Izod impact strength, joules/m.                                                                    294     961                                              Tensile strength, MPa.:                                                       At yield             50.0    47.8                                             At break             56.2    58.2                                             Tensile elongation, %                                                                              152     167                                              ______________________________________                                    

EXAMPLE 19

The procedure of Example 9 was repeated, employing the same resinousconstituents but substituting for the 20-mm. extruder a 28-mm.corotating, intermeshing twin screw extruder which was vacuum vented andcontained kneading block elements. Four runs were made at various screwspeeds and feed rates. The results are given in Table V; no delaminationwas observed.

                  TABLE V                                                         ______________________________________                                        Screw speed, rpm.                                                                              300     300     200   200                                    Feed rate, kg./hr.                                                                             18.2    9.1     11.8  9.1                                    Izod impact strength, joules/m.                                                                320     342     384   256                                    Tensile strength, MPa.:                                                       At yield         51.5    50.6    51.4  52.4                                   At break         58.4    63.1    54.2  65.1                                   Tensile elongation, %                                                                          147     205     101   210                                    ______________________________________                                    

What is claimed is:
 1. A composition comprising at least one polyamideand at least one aryloxytriazine-capped polyphenylene ether having endgroups of the formula ##STR8## wherein each Q¹ is independently halogen,primary or secondary lower alkyl, phenyl, haloalkyl, aminoalkyl,hydrocarbonoxy, or halohydrocarbonoxy wherein at least two carbon atomsseparate the halogen and oxygen atoms;each Q² is independently hydrogen,halogen, primary or secondary lower alkyl, phenyl, haloalkyl,hydrocarbonoxy or halohydrocarbonoxy as defined for Qhu 1; A is anunsubstituted or substituted aromatic radical; and X is an alkyl orcycloalkyl radical or an unsubstituted or substituted aromatic radical.2. A composition according to claim 1 wherein the polyphenylene ethercomprises a plurality of structural units having the formula ##STR9## 3.A composition according to claim 2 wherein the polyphenylene ether is apoly(2,6-dimethyl-1,4-phenylene ether).
 4. A composition according toclaim 3 wherein X is an aromatic radical.
 5. A composition according toclaim 3 wherein the polyamide is a polyamide-6 or a polyamide-66.
 6. Acomposition according to claim 5 which also contains an elastomericimpact modifier.
 7. A composition according to claim 6 wherein theimpact modifier is a triblock copolymer wherein the end blocks arederived from styrene and the midblock is derived from at least one ofisoprene and butadiene.
 8. A composition according to claim 7 whereinthe aliphatic unsaturation in the midblock has been removed by selectivehydrogenation.
 9. A composition comprising polyphenylene etherpolyamidecopolymer molecules containing at least one polyphenyleneether-polyamide linkage of the formula ##STR10## wherein: each Q¹ isindepedently halogen, primary or secondary lower alkyl, phenyl,haloalkyl, aminoalkyl, hydrocarbonoxy, or halohydrocarbonoxy wherein atleast two carbon atoms separate the halogen and oxygen atoms;each Q² isindependently hydrogen, halogen, primary or secondary lower alkyl,phenyl, haloalkyl, hydrocarbonoxy or halohydrocarbonoxy as defined forQ¹ ; and Z is an alkyl or cycloalkyl or unsubstituted or substitutedaromatic radical or -NH-.
 10. A composition according to claim 9 whereinthe polyphenylene ether comprises a plurality of structural units havingthe formula ##STR11##
 11. A composition according to claim 10 whereinthe polyphenylene ether is a poly(2,6-dimethyl-1,4-phenylene ether). 12.A composition according to claim 11 wherein Z is an aromatic radical.13. A composition according to claim 11 wherein Z is -NH-.
 14. Acomposition according to claim 11 wherein the polyamide is a polyamide-6or a polyamide-66.
 15. A composition according to claim 14 which alsocontains an elastomeric impact modifier.
 16. A composition according toclaim 15 wherein the impact modifier is a triblock copolymer wherein theend blocks are derived from styrene and the midblock is derived from atleast one of isoprene and butadiene.
 17. A composition according toclaim 16 wherein the aliphatic unsaturation in the midblock has beenremoved by selective hydrogenation.